Balloon wrap device

ABSTRACT

Apparatus for sequentially forming, wrapping and compressing a catheter balloon either during the initial manufacturing process or after a medical procedure. The balloon may be formed, wrapped and compressed by simply advancing the balloon through a balloon wrapping tool and selectively inflating and deflating the balloon therein. The balloon wrapping tool preferably includes a flap forming bore, a flap wrapping bore and a flap compression bore which form, wrap and compress the balloon, respectively, when the balloon is advanced therethrough.

FIELD OF THE INVENTION

The present application is related to balloon type catheter devices, andmore particularly to a method and apparatus for forming, wrapping andcompressing balloons to provide a reduced profile catheterconfiguration.

BACKGROUND OF THE INVENTION

Angioplasty has gained wide acceptance in recent years as an efficientand effective method for opening stenosis in the coronary arteries andin other parts of the vascular system. The most widely used form ofangioplasty makes use of a dilatation catheter which has an inflatableballoon at its distal end. Using fluoroscopy, the physician guides thecatheter through the vascular system until the balloon is positionedacross the stenosis. The balloon is then inflated by supplying a fluidunder pressure through an inflation lumen to the balloon. The inflationof the balloon causes stretching of the artery and pressing of thelesion into the artery wall to reestablish acceptable blood flow throughthe artery.

Intra-aortic balloon catheters have also gained wide acceptance inrecent years. Intra-aortic balloon catheters are typically inserted intothe aorta of the heart, often percutaneously, and then inflated anddeflated out of phase with the natural pumping action of the heart. Bydoing so, the intra-aortic balloon catheters can supplement the naturalpumping action of the heart. Both dilatation catheters and intra-aorticballoon catheters are balloon type catheters devices.

One important characteristic of balloon type catheters is the distal“profile”, which is determined by the outer diameter of the distal endportion of the balloon when deflated. This outer diameter affects theease and ability of the catheter to pass through a guide catheter,through the coronary arteries and/or across a tight lesion. Considerableeffort has been spent in developing low profile balloon type cathetersby minimizing the dimensions of the core or inner tube which extendsthrough the balloon to its distal end, and by reducing the wallthickness, to the extent possible, of the balloon itself.

A complicating factor in minimizing the deflated profile of a catheterballoon is that the balloon membrane is often not distensible, i.e. itdoes not stretch or contract in response to changes in internalpressure. This is typically true for both dilatation catheters andintra-aortic balloon type catheters. Thus, the balloon membranetypically has a constant surface area regardless of whether the balloonis inflated or deflated. To reduce the outer diameter of the ballooncatheter in its deflated condition, it is common to fold the balloonflat, so that two wings are brought together in some fashion, as byfolding or wrapping, so as to reduce the overall diameter of thedeflated balloon. In use, the inflation fluid that is applied to thefolded balloon causes the flaps to unwrap so that the balloon caninflate to its full inflated state.

While it is desirable to minimize the profile of the catheter, it isalso desirable to provide a large inflated outer diameter to theballoon. As the inflated outer diameter is made larger, the flaps of theballoon become relatively large relative to the core or inner tube ofthe catheter. The result is that it is often difficult to eliminate theinterstitial space between the flaps when folded together or wrappedaround the catheter.

Various methods and balloon configurations have been proposed in theprior art for providing a balloon type catheter that has the lowestprofile possible when deflated and the largest possible diameter wheninflated. One approach, which is suggested, for example, in U.S. Pat.No. 5,087,246 to Smith and in U.S. Pat. No. 5,147,302 to Euteneuer etal., is to provide a dilatation balloon having more than two flaps orwings (for example, three wings) such that when the flaps or wings arewrapped circumferentially, the distance that each flap extends aroundthe catheter is reduced when compared with the two flap configuration.The ease with which such flaps fold is also enhanced when the number isincreased, such that when the balloon is deflated and withdrawn throughthe guide catheter following a procedure, the balloon more readilyreturns to its wrapped condition. The result is a reduced deflatedprofile given the same inflated diameter.

Typically, the balloon flaps are formed during the manufacturing processof the catheter. U.S. Pat. No. 5,350,361 to Tsukashima et al. disclosesa method for preparing a tri-fold balloon configuration. Tsukashima etal. initially impart the tri-fold configuration to the balloon byinflating the balloon in a longitudinal interstitial channel defined bythree substantially cylindrical pins arranged in a pyramid-type stack.While the balloon is secured in this channel, negative pressure isapplied to an inflation lumen of the balloon to deflate the balloon,thus providing the tri-fold configuration to the balloon.

The balloon may be “heat set” in the desired fold configuration so thatthe balloon returns to the fold configuration when the balloon isdeflated. Tsukashima et al. suggest heating the creases defined by thethree tri-fold flaps with a longitudinal heating element. Thisapparently softens the balloon material in the longitudinal creases, sothat the same creases will tend to form whenever the balloon isdeflated.

Once the flaps are formed and/or set in the balloon, it is common tomanually fold the balloon flaps circumferentially around the catheter.The flaps are then typically held in place with a balloon protector. Aballoon protector typically serves two functions. First, the balloonprotector protects the balloon and the distal tip of the catheter frompossible damage during shipping. Second, the balloon protector wraps theballoon tightly in its deflated condition to minimize the outer diameterof the balloon in its deflated state.

A typical balloon protector is applied to the distal end portion of thecatheter prior to packaging and sterilization of the catheter. Thesterilization process often involves exposing the catheter, with theballoon protector in place, to an elevated temperature for apredetermined time period. With certain balloon materials, such aspolyolefin, the sterilization process causes the balloon to be “heatset” in the folded or wrapped condition in which it is held by theballoon protector. As a result, when the balloon protector is laterremoved, the balloon tends to remain in the tightly wrapped condition.

To further reduce the profile of the wrapped balloon, the balloonprotector can be constructed to be radially compressible. This furtherreduces the interstitial space in the wrapped balloon particularlyduring the heat setting process. Thus, when a balloon material is usedthat exhibits heat set characteristics, the deflated balloon will tendto remain tightly compressed even after removal of the balloonprotector.

While the prior art provides some improvement in the field of folding,wrapping and compressing balloon type catheters, there are still anumber of limitations, some of which are discussed below. One limitationis that the prior art balloon flaps are typically manually folded overthe catheter by an operator during the manufacturing process. This canbe a relatively slow and tedious process, and the quality of the wrap isoften dependent on the skill of the operator. Second, the balloonprotector must typically be installed over the wrapped balloon, whichcan also be a slow and tedious process. It would be desirable,therefore, to provide an apparatus and method that helps form, wrap andcompress the balloon flaps during the manufacturing process.

It would also be desirable to provide a tool that could be used by aphysician during a medical procedure to reform the flaps and rewrap theballoon. It has been found that once a balloon has been inflated torelatively high inflation pressures, the balloon material can loose theheat set characteristics provided during the manufacturing process. Forexample, a tri-fold balloon that has been inflated to relatively highpressures (10-15 atm) may take on a pancake shape having, for example,only two flaps when deflated. Further, the balloon may not return to theoriginal low profile wrap configuration. This can prohibit the crossingof additional lesions using the same catheter. To reach other lesions,the physician must often withdraw and discarded the catheter in favor ofa new catheter that has a balloon that was tightly wrapped during themanufacturing process.

SUMMARY OF THE INVENTION

The present invention overcomes many of the disadvantages of the priorart by providing a method and apparatus for sequentially forming,wrapping and compressing a catheter balloon during the initialmanufacturing process and/or during a subsequent medical procedure. Ineither case, the balloon may be formed, wrapped and compressed by simplyadvancing the balloon through a balloon wrapping tool, and selectivelyinflating and deflating the balloon therein according to the methodsdescribed below.

In one illustrative embodiment of the present invention, the balloonwrapping tool includes a flap forming section, a flap wrapping sectionand a flap compression section. The flap forming section has a flapforming bore extending therethrough that is shaped to produce at leasttwo flaps in the balloon when the balloon is inflated and subsequentlydeflated therein. The flap wrapping section, which is preferablypositioned adjacent to the flap forming section, has a flap wrappingbore extending therethrough that is axially aligned with the flapforming bore and shaped to wrap the at least two flaps around thecatheter as the deflated balloon is advanced therethrough. The flapcompression section is preferably positioned adjacent to the flapwrapping section, and includes a flap compression bore extendingtherethrough. The flap compression bore is preferably axially alignedwith the flap wrapping bore to receive the wrapped balloon. The wrappedballoon may be inflated and deflated in the flap compression bore tocompress the wrapped balloon and to set the creases therein.

An illustrative method of the present invention includes the steps of:inflating the balloon in the flap forming bore; deflating the balloon inthe flap forming bore to produce the at least two flaps in the balloon;and advancing the deflated balloon into the flap wrapping bore to wrapthe at least two flaps around the catheter as the deflated balloon isadvanced therethrough to provide a wrapped balloon. The illustrativemethod may further include the steps of: advancing the wrapped ballooninto the flap compression bore; inflating the wrapped balloon while inthe flap compression bore; deflating the wrapped balloon while in theflap compression bore; and removing the wrapped balloon from the flapcompression bore.

In one illustrative embodiment of the present invention, the balloonwrapping tool is initially separated from the catheter, and advanced ina proximal direction over the distal end of the balloon. In thisembodiment, the flap forming section is proximal of the flap wrappingsection, and the flap wrapping section is proximal of the flapcompression section. Once the balloon is positioned in the flap formingsection, the balloon is inflated and deflated, as described above. Theballoon wrapping tool is then advanced proximally until the balloon isin the flap wrapping section, and finally in the flap compressionsection. Once the balloon is successfully formed, wrapped andcompressed, the balloon wrapping tool is slid distally off the distalend of the catheter.

In another illustrative embodiment, the balloon wrapping tool isadvanced in a distal direction over the balloon. In this embodiment, theballoon wrapping tool is preferably provided in a coaxial arrangementwith the catheter shaft, and releasably secured to the manifold of thecatheter. Accordingly, the flap forming section is positioned distal ofthe flap wrapping section, and the flap wrapping section is positioneddistal of the flap compression section. In this configuration, and afterthe balloon has been inflated during a medical procedure andsubsequently withdrawn proximally from the body, the balloon wrappingtool is released from the manifold and advanced distally over thecatheter shaft until the flap forming section of the balloon wrappingtool is positioned over the balloon. The balloon is then inflated anddeflated to form the desired flap configuration in the balloon. Theballoon wrapping tool is then advanced distally until the balloon isprovided in the flap wrapping section, and finally in the flapcompression section. Once the balloon is successfully formed, wrappedand compressed, as described above, the balloon wrapping tool may beslid off the distal end of the catheter and discarded.

In another illustrative embodiment of the present invention, the balloonwrapping tool includes, from the proximal end to the distal end, a flapforming section, a flap wrapping section, a flap compression section andanother flap wrapping section. As described more fully below, thisillustrative embodiment may be particularly useful for wrapping and/orrewrapping the balloon of single operator exchange type device. In asingle operator exchange type device, the guide wire typically onlyextends from a proximal guide wire port, through the balloon, to adistal guide wire port. The proximal guide wire port is typicallylocated just proximal of the proximal end of the balloon. It is knownthat the guide wire typically provides significant column support forthe catheter shaft. Since the guide wire only extends through a distalportion of the single operator exchange type device, the catheter shaftjust proximal of the proximal guide wire port may have a reduced columnsupport.

To properly form the balloon, the flap forming section of the balloonwrapping tool preferably has a length that is at least as long as theballoon. When the balloon is advanced into the flap forming section orthe compression section, the operator or physician may not be able tograsp the catheter near the proximal guide wire port. Because of thelack of column support, and the inability of the operator or physicianto grasp the catheter sufficiently close to the proximal guide wireport, it may not be possible to advance the balloon of a single operatorexchange type device into the flap wrapping section and/or flapcompression section, as described above.

Accordingly, after the balloon is inflated and deflated in the flapforming section, the balloon may be withdrawn from the balloon wrappingtool. The balloon may then be inserted into the second flap wrappingsection, which in this embodiment, is located on the opposite side ofthe compression section from the flap forming section. Alternatively,the flap wrapping section can be adjacent to the other sections. Sinceno flap forming section is provided adjacent to the second flap wrappingsection, the operator or physician may grasp the catheter shaft near theproximal guide wire port, and provide the needed column support. Thus,the operator or physician may advance the balloon into the second flapwrapping section and the flap compression section to complete theforming, wrapping and compression of the balloon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first illustrative balloon wrappingtool in accordance with the present invention;

FIG. 2 is a cross-sectional side view of the balloon wrapping tool ofFIG. 1, taken along line 2—2;

FIG. 3 is a cross-sectional view of the balloon wrapping tool of FIG. 2,taken along line 3—3;

FIG. 4 is a cross-sectional view of the balloon wrapping tool of FIG. 2,taken along line 4—4;

FIG. 5 is a cross-sectional view of the balloon wrapping tool of FIG. 2,taken along line 5—5;

FIG. 6 is a cross-sectional view of the balloon wrapping tool of FIG. 2,taken along line 6—6;

FIG. 7 is a cross-sectional view of the flap forming section of anotherillustrative balloon wrapping tool for forming four balloon wings;

FIG. 8 is a cross-sectional view of the flap forming section of anotherillustrative balloon wrapping tool for forming five balloon wings;

FIG. 9 is a cross-sectional view of the flap forming section of yetanother illustrative balloon wrapping tool including three movablemembers;

FIG. 10 is a cross-sectional view of the flap forming section of theillustrative balloon wrapping tool of FIG. 9, with the three movablemembers extending inwardly;

FIG. 11 is a perspective view of another illustrative balloon wrappingtool in accordance with the present invention having a spiralconfiguration;

FIG. 12 is a cross-sectional side view of the balloon wrapping tool ofFIG. 11, taken along line 12—12;

FIG. 13 is a cross-sectional view of the balloon wrapping tool of FIG.12, taken along line 13—13;

FIG. 14 is a cross-sectional view of the balloon wrapping tool of FIG.12, taken along line 14—14;

FIG. 15 is a cross-sectional view of the balloon wrapping tool of FIG.12, taken along line 15—15;

FIG. 16 is a cross-sectional view of the balloon wrapping tool of FIG.12, taken along line 16—16;

FIG. 17 is a cross-sectional side view of a balloon wrapping tool thatincludes a lubricious coating on the inside surface thereof;

FIG. 18 is a cut-away view of an illustrative inner surface of yetanother illustrative balloon wrapping tool;

FIG. 19 is a partial cross-sectional side view of the compressionsection of another illustrative balloon wrapping tool;

FIG. 20 is a perspective view of yet another illustrative balloonwrapping tool in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a first illustrative balloon wrapping tool isgenerally shown at 10. The balloon wrapping tool 10 includes a flapforming section 12, a flap wrapping section 14 and a flap compressionsection 16. The flap forming section 12 has a flap forming bore 18extending therethrough that is shaped to produce at least two flaps inthe balloon when the balloon is inflated and subsequently deflatedtherein. The flap wrapping section 14, which is preferably positionedadjacent to the flap forming section 12 as shown, has a flap wrappingbore extending therethrough that is axially aligned with the flapforming bore 18. The flap wrapping bore is shaped to wrap the at leasttwo flaps around the catheter as the deflated balloon is advancedtherethrough. The flap compression section 16 is preferably positionedadjacent to the flap wrapping section 14, and includes a flapcompression bore extending therethrough. The flap compression bore ispreferably axially aligned with the flap wrapping bore to receive thewrapped balloon. The wrapped balloon may be inflated and deflated in theflap compression bore to compress the wrapped balloon and to set thecreases therein.

An illustrative method of the present invention includes the steps of:inflating the balloon 20 of a catheter 22 in the flap forming bore 18 topreferably about eight atmospheres for five seconds (this pressure mayvary depending on balloon material and other conditions); deflating theballoon 20 in the flap forming bore 18 to produce the at least two flapsin the balloon 20; and advancing the deflated balloon 20 into the flapwrapping bore of the flap wrapping section 14 to wrap the at least twoflaps around the catheter as the deflated balloon 20 is advancedtherethrough to provide a wrapped balloon. The illustrative method mayfurther include the steps of: advancing the wrapped balloon 20 into theflap compression bore of the flap compression section 16; inflating thewrapped balloon 20 while in the flap compression bore to preferablyabout 3-5 atmospheres for five seconds; deflating the wrapped balloon 20while in the flap compression bore; and removing the wrapped balloon 20from the flap compression bore. Finally, to facilitate the advancementof the catheter through the balloon wrapping tool 10, it is contemplatedthat a mandrel or guide wire may first be positioned through the balloonwrapping tool 10, and the catheter may be back-loaded over the mandrel.The mandrel provides additional column support to the catheter therebyincreasing the pushability of the catheter.

In one illustrative embodiment of the present invention, the balloonwrapping tool 10 is initially separated from the catheter 22, andadvanced in a proximal direction over the distal end of the balloon 20.In this embodiment, the flap forming section 12 is proximal of the flapwrapping section 14, and the flap wrapping section 14 is proximal of theflap compression section 16. Once the balloon is positioned in the flapforming section 12, the balloon is inflated and deflated, as describedabove. The balloon wrapping tool is then advanced proximally, relativeto the catheter 20, until the balloon 20 is in the flap wrapping section14, and finally in the flap compression section 16. Once the balloon issuccessfully formed, wrapped and compressed, the balloon wrapping tool10 is slid distally off the distal end of the catheter 22.

In another illustrative embodiment, the balloon wrapping tool 10 isadvanced in a distal direction down the shaft of the catheter and overthe balloon. In accordance with this embodiment, and referring to FIG.1, the balloon wrapping tool 10 can be provided in a coaxial arrangementwith a catheter shaft 32, and releasably secured to a manifold 36 of thecatheter 30. The flap forming section 12 is positioned distal of theflap wrapping section 14, and the flap wrapping section 14 is positioneddistal of the flap compression section 16 relative to the catheter 30.In this configuration, and after the balloon 34 has been inflated duringa medical procedure and subsequently withdrawn proximally from the body,the balloon wrapping tool 10 is released from the manifold 36 of thecatheter 30 and advanceddistally over the catheter shaft 32 until theflap forming section 12 of the balloon wrapping tool 10 is positionedover the balloon 34. The balloon 34 is then inflated and deflated toform the desired flap configuration in the balloon 34. The balloonwrapping tool 10 is then advanced distally until the balloon 34 isprovided in the flap wrapping section 14, and finally in the flapcompression section 16. Once the balloon is successfully formed, wrappedand compressed, as described above, the balloon wrapping tool 10 may beslid off the distal end of the catheter 30 and discarded, or can be slidback down the shaft and resecured at the proximal hub. The position ofcatheter 30 in FIG. 1 shows the balloon 34 successfully wrapped and theballoon wrapping tool 10 slid off the distal end of the catheter 30.

FIG. 2 is a cross-sectional side view of the balloon wrapping tool 10 ofFIG. 1, taken along line 2—2. The flap forming section 12 has a flapforming bore 18, the flap wrapping section 14 has a flap wrapping bore37, and the flap compression section 16 has a flap compression bore 39.The flap forming bore 18, flap wrapping bore 37 and the flap compressionbore 39 are preferably axially aligned to allow easy insertion of theballoon 20 therethrough. The size and shape of the proximal end of theflap wrapping bore 37 preferably substantially matches the size andshape of the distal end of the flap forming bore 18. Likewise, the sizeand shape of the distal end of the flap wrapping bore 37 substantiallymatches the size and shape of the proximal end of the flap compressionbore 39. Thus, the flap wrapping bore provides a transition from theflap forming bore 18 to the flap compression bore 29. The flapcompression bore 39 is preferably dimensioned to be near the desiredprofile of the wrapped balloon 20, but may have a slight inward tapertoward the distal end to provide the lowest possible profile to thedistal end of the balloon.

FIG. 3 is a cross-sectional view of the balloon wrapping tool 10 of FIG.2, taken along line 3—3, and showing the cross-section of the flapforming section 12. In this embodiment, the flap forming bore 18 issubstantially triangular in shape with three arcuate shaped sidesurfaces 40 a, 40 b and 40 c. When the balloon 20 is inflated andsubsequently deflated in the flap forming bore 18, the balloon will havethree equally spaced flaps.

FIG. 4 is a cross-sectional view of the balloon wrapping tool of FIG. 2,taken along line 4—4, and showing the cross-section of the proximalportion of the flap wrapping section 14. As indicated above, the sizeand shape of the proximal end of the flap wrapping bore 37 substantiallymatches the size and shape of the distal end of the flap forming bore18. Thus, at line 4—4, the flap wrapping bore 37 has transitioned fromthe shape shown in FIG. 3 to more of a triangle shape. FIG. 5 showing across-section of a distal portion of the flap wrapping section 14, andspecifically along line 5—5. The size and shape of the distal end of theflap wrapping section 14 preferably substantially matches the size andshape of the proximal end of the flap compression bore 39. Thus, at line5—5, the flap wrapping bore 37 has transitioned from the shape shown inFIG. 4 to more of a rounded-off triangle shape.

FIG. 6 is a cross-sectional view of the balloon wrapping tool of FIG. 2,taken along line 6—6, showing the cross-section of the ballooncompression bore 39. The balloon compression bore 39 is preferablysubstantially round and has a diameter that is near the desired wrappedballoon profile.

FIG. 7 is a cross-sectional view of a flap forming section of anotherillustrative balloon wrapping tool. In this embodiment, the flap formingsection has a flap forming bore 50 that is substantially X-shaped withfour arcuate shaped side surfaces 52 a, 52 b, 52 c and 52 d. When theballoon 20 is inflated and subsequently deflated in the flap formingbore 50, the balloon will have four equally spaced flaps.

FIG. 8 is a cross-sectional view of the flap forming section of yetanother illustrative balloon wrapping tool. In this embodiment, the flapforming section has a flap forming bore 54 that is substantiallystar-shaped having five inwardly extending grooves 56 a, 56 b, 56 c, 56d and 56 e. When the balloon 20 is inflated and subsequently deflated inthe flap forming bore 54, the balloon will have five equally spacedflaps.

FIG. 9 is a cross-sectional view of the flap forming section of yetanother illustrative balloon wrapping tool including three movableprotrusions. In this embodiment, the flap forming section includes aflap forming bore 60 with three slots for receiving the spaced elongateprotrusions 62 a, 62 b and 62 c. Before the balloon is inserted into theflap forming bore 60, the elongate protrusions 62 a, 62 b and 62 c areplaced in an outward position, as shown in FIG. 9. After the balloon isinserted into the flap forming bore 60, the elongate protrusions 62 a,62 b and 62 c are moved inward toward the balloon, as shown in FIG. 10.Thereafter, the balloon is inflated and subsequently deflated to formthree equally spaced flaps. The elongate protrusions 62 a, 62 b and 62 cmay then be moved back to the outward position shown in FIG. 9.

FIG. 11 is a perspective view of a another illustrative balloon wrappingtool in accordance with the present invention. The balloon wrapping toolof this embodiment also has a flap forming section 100, a flap wrappingsection 102 and a flap compression section 104. The flap forming section100 and flap compression section 104 are similar to that shown in FIG.1. However, the flap wrapping section 102 has a spiral shape to helpfold the balloon flaps in a single direction around the catheter.

FIG. 12 is a cross-sectional side view of the balloon wrapping tool ofFIG. 11, taken along line 12—12, showing the flap forming section 100,flap wrapping section 102 and the flap compression section 104. Theshape of the flap wrapping section 102, which substantially matches theshape of the flap forming section 100 at its proximal end, is graduallyrotated radially about the central axis of the balloon wrapping tool. Atthe same time, the dimensions of the flap wrapping bore are reduced tomatch the size and shape of the balloon compression bore at its distalend. This change in shape urges the flaps of the balloon to wrap aroundthe catheter in a single direction when the balloon is insertedtherethrough.

FIG. 13 is a cross-sectional view of the balloon wrapping tool of FIG.12, taken along line 13—13. The balloon is shown having three flaps 110a, 110 b and 110 c each positioned within one of the three regions 114,116 and 118. The flaps are shown just beginning to fold over thecatheter 112, all in the same direction. As the balloon is advancedfurther into the flap wrapping section 102, as shown more fully in FIG.14, the three flaps 110 a, 110 b and 110 c are further folded over thecatheter 112. The three regions 114, 116 and 118 are shown as rotated tothe left. In these figures, the balloon wrapping tool has not beenrotated. Rather the shape of the flap wrapping section 102 has changed.As the balloon is advanced further into the flap wrapping section 102,as shown more fully in FIG. 15, the three flaps 110 a, 110 b and 110 care further folded over the catheter 112. Finally, FIG. 16 shows theballoon advanced into the flap compression section 104. In the flapcompression section, the three flaps 110 a, 110 b and 110 c are fullyfolded over the catheter 112 and ready for compression.

FIG. 17 is a cross-sectional side view of a balloon wrapping tool thatincludes a lubricious coating on the inside surface thereof. In somecases, the friction between the balloon and the balloon wrapping toolmay be significant, particularly when advancing the balloon into thecompression section. Thus, it is contemplated that a lubricious layer130 may be provided on the surfaces of the flap forming bore, the flapwrapping bore and/or the flap compression bore. Alternatively, or inaddition to, the surfaces of the flap forming bore, the flap wrappingbore and/or the flap compression bore may include a pattern ofprojections to reduce the frictional forces, such as the dimple patternshown in FIG. 18.

FIG. 19 is a partial cross-sectional side view of the compressionsection of another illustrative balloon wrapping tool. In thisembodiment, the compression section includes one or more slits 150 alonga portion thereof. The slit allows the compression section to assume areduced diameter when compressed by a compression tool 152. Preferably,the compression tool has an inner bore 154 that reduces in diametertoward the distal end 158 thereof. After the balloon is positioned inthe compression section, the proximal end 156 of the compression tool152 may be slid over the compression section of the balloon wrappingtool as shown. Because the diameter of the inner bore 154 reduces towardthe distal end 158 thereof, the balloon becomes further compressed asthe compression tool 152 is advanced proximally. The compression tool152 may be advanced proximally until the desired balloon profile isachieved.

FIG. 20 is a perspective view of yet another illustrative balloonwrapping tool in accordance with the present invention. In thisembodiment, the balloon wrapping tool 160 includes, from the proximalend to the distal end, a flap forming section 162, a first flap wrappingsection 164, a flap compression section 166 and a second flap wrappingsection 168. This illustrative embodiment may be particularly useful forwrapping and/or rewrapping the balloon of a single operator exchangetype device. In a single operator exchange type device, the guide wiretypically only extends through a short guide wire lumen that extendsthrough the distal end of the catheter. The guide wire typically entersa guide wire port 170 that is located proximate the balloon, and extendsout the distal end of the catheter. Typically, the guide wire providessignificant column support for the catheter shaft. Since the guide wireonly extends through a relatively short distal portion of a singleoperator exchange type device, the guide wire does not providesignificant column support to the catheter shaft that is proximal to theguide wire port 170.

To properly form the balloon, the flap forming section 162 of theballoon wrapping tool 160 preferably has a length that is at least aslong as the balloon. When the balloon is positioned within the flapforming section 162, the operator or physician will likely be able tograsp the catheter shaft at or distal of the proximal guide wire port170. For some single-operator exchange type catheters, the operator willalso be able to grasp the catheter shaft near the proximal guide wireport 170 even as the balloon is advanced into the flap wrapping section164. However, as the balloon is advanced into the flap compressionsection 166, the operator may not be able to grasp the catheter shaftsufficiently close to the proximal guide wire port 170, and the cathetermay lack the column support to allow the balloon to be pushed into thecompression section 166 without kinking. Because of the lack of columnsupport, and the inability of the operator or physician to grasp thecatheter sufficiently close to the proximal guide wire port, it may notbe possible to advance the balloon of a single operator exchange typedevice into the flap wrapping section 166 and/or the flap compressionsection, as described above.

Accordingly, after the balloon is inflated and deflated in the flapforming section 162, the balloon may be withdrawn from the balloonwrapping tool 160, as shown by arrows 176. The balloon may then beinserted into the flap wrapping section 168, which in this embodiment,is located on the opposite side of the compression section 166 from theballoon forming section 162. This is indicated by arrows 177. Since noflap forming section is provided adjacent to the flap wrapping section168, the operator or physician may grasp the catheter shaft near theproximal guide wire port 170, and provide the needed column support toadvance the balloon into the flap wrapping section 168 and flapcompression section 166. Thus, the operator or physician may advance theballoon into the flap wrapping section 168 and the flap compressionsection 166 to complete the forming, wrapping and compression of theballoon.

Numerous characteristics and advantages of the invention covered by thisdocument have been set forth in the foregoing description. It will beunderstood, however, that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of parts without exceeding the scope of theinvention. The invention's scope is, of course, defined in the languagein which the appended claims are expressed.

What is claimed is:
 1. Apparatus for wrapping a balloon of a ballooncatheter, comprising: a tubular member having a flap forming section anda flap wrapping section; the flap forming section having a flap formingbore extending therethrough, the flap forming bore having a shape thatproduces at least three flaps in the balloon when the balloon isinflated and subsequently deflated therein; and the flap wrappingsection having a flap wrapping bore extending therethrough, wherein theflap wrapping bore is axially aligned with the flap forming bore, andhas a shape that wraps the at least three flaps of the balloon onto thecatheter as the deflated balloon is advanced therethrough.
 2. Apparatusaccording to claim 1 wherein the flap forming bore is substantiallytriangular in shape with three arcuate shaped side surfaces. 3.Apparatus according to claim 1 wherein the flap forming bore issubstantially X-shaped.
 4. Apparatus according to claim 1 wherein theflap forming bore includes three or more spaced outward extendinggrooves.
 5. Apparatus according to claim 1 wherein the flap formingsection includes three or more spaced elongate protrusions extendinginwardly into the flap forming bore.
 6. Apparatus according to claim 1wherein the flap wrapping bore has a proximal end with a first shape anda distal end with a second shape, wherein the first shape of theproximal end substantially matches the shape of the flap forming bore,and the second shape of the distal end is substantially circular. 7.Apparatus according to claim 6 wherein the flap forming bore includesthree or more spaced outward extending grooves.
 8. Apparatus accordingto claim 7 wherein the flap wrapping bore includes three or more spacedoutward extending grooves aligned with the grooves of the flap formingbore, the outward extending grooves of the flap wrapping bore have adepth that decreases from the proximal end to the distal end of the flapwrapping bore.
 9. Apparatus according to claim 8 wherein the grooves ofthe flap wrapping bore are provided in a cork screw configuration. 10.Apparatus according to claim 6 wherein the flap forming section includesthree or more spaced elongate protrusions extending inwardly into theflap forming bore.
 11. Apparatus according to claim 10 wherein the flapwrapping section includes three or more spaced elongate protrusionsextending inwardly into the flap wrapping bore and aligned with theprotrusions of the flap forming section, the inward extendingprotrusions of the flap wrapping section have a height that decreasesfrom the proximal end to the distal end of the flap wrapping section.12. Apparatus according to claim 11 wherein the protrusions of the flapwrapping section are provided in a cork screw configuration. 13.Apparatus according to claim 1 wherein the flap forming section includesthree or more spaced elongate protrusions extending inwardly into theflap forming bore.
 14. Apparatus for wrapping a balloon of a ballooncatheter, comprising: a tubular member having a flap forming section, aflap wrapping section and a flap compression section; the flap formingsection having a flap forming bore extending therethrough, the flapforming bore having a shape that produces at least three flaps in theballoon when the balloon is inflated and subsequently deflated therein;the flap wrapping section having a flap wrapping bore extendingtherethrough, wherein the flap wrapping bore is axially aligned with theflap forming bore, and has a shape that wraps the at least three flapsof the balloon onto the catheter as the deflated balloon is advancedtherethrough; the flap compression section having a compression boreextending therethrough, wherein the compression bore is axially alignedwith the flap wrapping bore.
 15. Apparatus for wrapping a balloon of aballoon catheter, comprising: a first tubular section having a proximalend and a distal end and a flap forming bore extending therethrough; asecond tubular section having a proximal end and a distal end, whereinthe proximal end of the second tubular section is adjacent the distalend of the first tubular section, and said second tubular section havinga flap wrapping bore extending from the proximal end to the distal endof the second tubular section, wherein the flap wrapping bore is influid communication with the flap forming bore of the first tubularsection; a third tubular section having a proximal end and a distal endwherein the proximal end of the third tubular section is adjacent thedistal end of the second tubular section, said third tubular sectionhaving a flap compression bore that is in fluid communication with theflap wrapping bore of the second tubular member; said flap forming borehaving a shape that produces at least three flaps when the balloon isinflated and subsequently deflated therein; said flap compression borehaving a different size and shape from the flap forming bore; and saidflap wrapping bore providing a transition form the flap forming bore tothe flap compression bore, and having a shape that causes the at leastthree flaps of the balloon to become wrapped around the catheter whenthe balloon is advanced from the flap forming bore to the flapcompression bore.
 16. Apparatus according to claim 15 further comprisinga fourth tubular section having a proximal end and a distal end, whereinthe proximal end of the fourth tubular section is adjacent the distalend of the third tubular section, said fourth tubular section having aflap wrapping bore extending from the proximal end to the distal end ofthe fourth tubular section, wherein the flap wrapping bore is in fluidcommunication with the flap compression bore of the third tubularsection, said flap wrapping bore of the fourth tubular section having ashape that causes the at least three flaps of the balloon to becomewrapped around the catheter when the balloon is advanced from the flapforming bore of the fourth tubular section to the flap compression boreof the third tubular section.